When i got my D ( 1999), i had the A/C flushed and refridg added, and checked the lines, seemed fine, blew cold air. now, a few weeks later,on a/c it blows only warm air on the front vents and HOT air on the floor vents. whats up with that?

 

My guess is that you have a coolant leak somewhere. The first gen D's are known to having the evap leak. Before jumping to any conclusions tho, either put dye in it yourself or have someone else do it to verify it and where it is leaking. That's the first step. Depending on where it is leaking, will depend on how bad the reapir will be. Post what you find, there are a lot of very helpful people on this forum.